Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
For several reasons, it is highly desirable to identify counterfeit or fraudulent documents, such as to identify fraudulent products with counterfeit packaging and/or other identifying information. Advancing technology, such as improved software applications, printers and copiers, has enabled the proliferation of counterfeit documents. For example, grey market or knock-off goods are difficult to distinguish from authentic and/or authorized goods. Identifying a product as authentic based on its packaging or other documentation is especially important when dealing with products, such as pharmaceutical products, where the effect of a counterfeit product may be life-threatening. As additional examples, a counterfeit vehicle title can be very costly to an unsuspecting purchaser, and fake coupons can be costly to a business. Therefore, it is important to develop a method for providing tamper-resistant security information in documents along with the ability to readily authenticate that security information.